1/* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
2/*
3 * Copyright (c) 2015-2019, Arm Limited and Contributors. All rights reserved.
4 * Copyright (C) 2019-2020, Linaro Limited
5 *
6 * An SCMI agent device represent on communication path from a
7 * device driver to the remote SCMI server which driver sends
8 * messages to and receives response messages from.
9 */
10#ifndef SCMI_AGENT_H
11#define SCMI_AGENT_H
12
13#include <scmi_protocols.h>
14#include <asm/types.h>
15
16struct udevice;
17struct scmi_channel;
18
19/**
20 * struct scmi_agent_proto_priv - Private data in device for SCMI agent
21 * @channel: Reference to the SCMI channel to use
22 */
23struct scmi_agent_proto_priv {
24	struct scmi_channel *channel;
25};
26
27/*
28 * struct scmi_msg - Context of a SCMI message sent and the response received
29 *
30 * @protocol_id:	SCMI protocol ID
31 * @message_id:		SCMI message ID for a defined protocol ID
32 * @in_msg:		Pointer to the message payload sent by the driver
33 * @in_msg_sz:		Byte size of the message payload sent
34 * @out_msg:		Pointer to buffer to store response message payload
35 * @out_msg_sz:		Byte size of the response buffer and response payload
36 */
37struct scmi_msg {
38	unsigned int protocol_id;
39	unsigned int message_id;
40	u8 *in_msg;
41	size_t in_msg_sz;
42	u8 *out_msg;
43	size_t out_msg_sz;
44};
45
46/* Helper macro to match a message on input/output array references */
47#define SCMI_MSG_IN(_protocol, _message, _in_array, _out_array) \
48	(struct scmi_msg){			\
49		.protocol_id = (_protocol),	\
50		.message_id = (_message),	\
51		.in_msg = (uint8_t *)&(_in_array),	\
52		.in_msg_sz = sizeof(_in_array),	\
53		.out_msg = (uint8_t *)&(_out_array),	\
54		.out_msg_sz = sizeof(_out_array),	\
55	}
56
57/**
58 * devm_scmi_of_get_channel() - Get SCMI channel handle from SCMI agent DT node
59 *
60 * @dev:	Device requesting a channel
61 * @return 0 on success and a negative errno on failure
62 */
63int devm_scmi_of_get_channel(struct udevice *dev);
64
65/**
66 * devm_scmi_process_msg() - Send and process an SCMI message
67 *
68 * Send a message to an SCMI server through a target SCMI agent device.
69 * Caller sets scmi_msg::out_msg_sz to the output message buffer size.
70 * On return, scmi_msg::out_msg_sz stores the response payload size.
71 *
72 * @dev:	SCMI device
73 * @msg:	Message structure reference
74 * Return: 0 on success and a negative errno on failure
75 */
76int devm_scmi_process_msg(struct udevice *dev, struct scmi_msg *msg);
77
78/**
79 * scmi_get_protocol() - get protocol instance
80 *
81 * @dev:	SCMI agent device
82 * @id:		SCMI protocol ID
83 *
84 * Obtain the device instance for given protocol ID, @id.
85 *
86 * Return:	Pointer to the device if found, null otherwise
87 */
88struct udevice *scmi_get_protocol(struct udevice *dev,
89				  enum scmi_std_protocol id);
90
91/**
92 * scmi_to_linux_errno() - Convert an SCMI error code into a Linux errno code
93 *
94 * @scmi_errno:	SCMI error code value
95 * Return: 0 for successful status and a negative errno otherwise
96 */
97int scmi_to_linux_errno(s32 scmi_errno);
98
99#endif /* SCMI_H */
100